We found this circuit in a 1998 publication. The circuit has controls for both frequency and signal strength. A lamp is used to monitor the signals. The supply is made with a voltage of 12 V.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This circuit turns on an old cassette recorder when the telephone rings, thus enabling the...
This circuit can be used in panel signaling with common incandescent lamp. The lamp will flash at a...